Exam2Lec4Neisseria, Haemophilus, & Anaerobes Flashcards
What is the morphology of the genus Neisseria ?
Gram negative cocci
What are the two important species of neisseria?
Gonorrhoeae
meningitidis
Where is neisseria found?
around and inside of neutrophils
What is the spectrum of the disease (neisseria)?
Systemic, life-threatening disease
neisseria meingococci is found where?
Upper respiratory tract
neisseria gonococci is found where?
Genital tract
Details of neisseria species
gram negative, non-motile encapsulated, diplococcus, kidney shaped
aerobic but can grow without oxygen as a facultative anaerobe
fastidious growth
What media does neisseria species grow on? and for how long?
modified Thayer-martin medium or chocolate agar for 48 hours
What is the host of neisseria meningitidis ?
humans are the only natural hosts
What is the portal of entry of neisseria meningitidis?
nasopharynx
What are 3 major factors/ virulence factors of n. meningitidis?
Pili: colonization of nasopharynx–> become transient flora
Capsule–>systemic spread: bacteremia and meningitis
lps/los
No Man Picks Chick Last
What are the diseases of neisseria meningitidis ?
SPAMS Baby Daddy
Purpura fulminans
Meningitis
Septicemia
bacteremia
Arthritis
Shock
Death
What causes systemic spread of neisseria meningitidis ?
capsule
How can we classify N. meningitidis ?
Serogroups
–polysaccharide capsule: A,B, C, Y, W-135
What is the importance of serogroups of N.meningitdis?
Relation to disease:
-certain serogroups relate to disease
-public health tracking of outbreaks
-Development of vaccines
Protection of N.meningitidis requires what?
antibodies and complement
What is the N.meningitidis vaccine?
-Groups A,C, Y and W-135 polysaccharide conjugated to protein carrier (diphtheria toxoid Menactra®)
-Recommended for all 11-12 year olds, others based on risk factors
-Separate group B vaccine
What is the age recommendation for n.meningitdis vaccine?
11-12 years old
Clinical case :
- 3 year old baby is taken to the ER -fever & lethargy for 1 day, petechial rash & purpuric lesions, listless
- Blood cultures, IV antibiotics, hospital
- Lumbar puncture - CSF – white blood cells, (94% PMNs)
- Blood cultures positive for Gram negative diplococci,
N. meningitdis
What is the treatment of N.meningitis
antibiotics: penicillin, third generation cephalosporin (vefotazime, ceftriaxonr)
MEDICAL EMERGENCY
What is the symptoms of N. Meningitis?
Stiff neck
petechial rash
purpuric lesions
WBC in CSP
Gram negative diplococci in blood
What are the virulence factors of N. gonorrhoeae?
CROP LIP
Pili: responsible for attachment to host epithet cells
IgA protease: cleaves IgA molecule
Capsule
OPA: assist piling attachment
LOS: endotoxin activity
Por proteins: forms pores through outer membrane
Rmp proteins: inhibits cidal activity of serum
What are the surface factors of N. gonorrhoeae ?
Pili
IGA protease
Capsule
Opa
LOS
Role of pili in N. gonorrhoeae
Responsible for attachment to host epithelial cells
Role of IgA protease in N. gonorrhoeae
Cleaves IgA molecule
role of capsule in N. gonorrhoeae
avoid phagocytosis
role of opa in N. gonorrhoeae
assist in pili in attachment
role of LOS in N. gonorrhoeae
Endotoxin activity
Why is neisseria gonorrhoeae such a successful pathogen
antigenic variation
Example antigenic variation
Multiple copies (10-15) of pilin gene
Recombination (splicing) of one of the copies of the pilin gene (pilS) with the control regions (pilE)
Recombination within PilS
What is the clinical presentation of N. gonorrhoeae ?
Urethritis
Cervicitis
Salpingitis
proctitis
Pharyngitis
Arthritis
conjunctivitis
PID
Septicemia
What is the reservoir for N. gonorrhoeae
humans only reservoir-asymptomatic carrier
Who is at the highest risk for n. gon?
Teens and young adults
What is the transmission of N. gonorrhoeae
Sexual contact primary
What is the clinical presentation in men of N. gonorrhoeae ?
-usually symptomatic
-2 to 7 days post infection:
urethral discharge “the drips”
dysuria
complications are rare
rectal and pharyngeal infections
Female or male have higher chance of complication of n. gonorrhea
female
Female or male are more symptomatic
males
What is the clinical presentation of n. gonorrhea in WOMEN?
-frequently mild or asymptomatic
-vaginal discharge, dysuria, abdominal pain
-complications are common (10-20% of cases)
-ascending genital infection causes salpingitis, and PID
-rectal and pharyngeal infections
Both male and females infected with N. gonorrhea can get?
rectal and pharyngeal infections
What is PID (N. gonorrhea)?
Pelvic inflammatory disease
Complication of untreated N. gonorrhea
painful and may require surgical drainage or in severe causes hysterectomy
What is DGI ( N. gonorrhea )?
Disseminated gonococcal infection
N. gonorrhea in cirulatory system
Commonly includes septic arthritis
What is opthhalmia neonatorum (N. gonorrhea)? IMP
conjuctivitis resulting from vaginal delivery with infected mother
prevented with eye drops
How do we diagnosis gonorrhea
Direct Gram stain - effective for urethral discharge in symptomatic men
Gram (-) diplococci
Culture on chocolate agar or selective media
Oxidase +
Utilization of glucose confirmatory
What is the oxidase result of n. gonorrhea
positive–> purplish
What is the oxidase result of n. gonorrhea
positive–> purplish
What is the treatment of n. gonorrhea?
3rd generation cephalosporin with azithromycin and doxycycline
penicillin resistance now common due to mutated PBP and plasmid encoded beta-lactamase
sexual contacts should be treated to prevent “ping pong” infections
What is n. gonorrhea resistant to
penicillin resistance now common due to mutated PBP and plasmid encoded beta-lactamase
n. gonorrhea can be prevented through what ?
education and safe sex
What is the morphology of haemophilus influenzae ?
Gram negative coccobacilli
Fastidious
H. influenzae can have strain that contain what?
may have polysaccharide capsule which determines serotype (a-f) -invasive disease
what version of H. influenzae is not as invasive
non-encapsulated
What are the virulence factors of H. influenzae
Capsule
Endotoxin
IgA protease
Pili for adherence